Rings Around Earth From Ancient Meteorites 162
HorsePunchKid writes "According to an article on CNN (SNL version), ancient meteorites may have glanced off of the surface and shattered, causing rings around the Earth. These rings, which may have persisted for hundreds of thousands of years, could have had a profound effect on the climate in tropical regions, where the rings would block out light from the Sun. Still rather speculative, but the theory may help explain some patterns observed in the geological record. The idea has been around for a while, and some scientists are skeptical."
I still favour the fire theories... (Score:5, Insightful)
Said impact ejecta would be thrown up and into the stratosphere, circle, and land somewhere opposite (say 3/4) around the globe. More impacts, more fire. Lots of soot to block out light.
I can see a 'ring' of debris specifically targetting the tropics region, but i just have trouble dealing with the numbers of objects required to decrease the light that significantly resulting in a sphere of Earths size being cooled that significantly.
Suffice to say, the ring is there, but I'd still throw my support behind half the planet burning up as a more tangible reason.
Re:I still favour the fire theories... (Score:2)
Except that a fire that large would leave a layer of soot that could be detected, and no such soot has been detected (at least at the 35 million year climate disturbance).
Re:I still favour the fire theories... (Score:2, Interesting)
Some say in ice.
From what I've tasted of desire
I hold with those who favour fire.
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
And would suffice.
--Robert Frost
Re:I still favour the fire theories... (Score:1)
Re:I still favour the fire theories... (Score:1)
Re: Robin Canup must "get" it (Score:1)
It don't mean a thing if it ain't got that swing . .
Re: Robin Canup must "get" it (Score:2)
Damn Martians.... (Score:1)
Wrong (Score:3, Funny)
This is totally unbelievable. The climate change is totally man caused, and we are the only people that can change it.
Re:Wrong (Score:1)
According to Yahoo!, the Sahara Desert is in 'spectacular' retreat. This is manifestly a Good Thing, and therefore can't have anything to do with human induced Global Warming, which only causes Bad Things.
Re:Wrong (Score:1)
Re:Wrong (Score:2, Interesting)
Re:Wrong (Score:1, Flamebait)
Would you also like to explain the marks left behind by the glaciers and the things such as mammoths we have found frozen in them? Everything points to there having been ice ages in the past, even during times when the human race was around.
Also, unless I am terribly mistaken, we had a much more tropical Earth during the reign of the dinosaurs and very very small ice caps. All geologic and evolutionary evidence points to the fact that the Earth has had its warm times and its cold times.
Humans may be effecting the climate now, but we may only be nudging along a warming trend for all we know. We just don't have enough data to know for sure yet.
Re:Wrong (Score:3, Funny)
Yup
Anyhoo, the only reason I personally worry about humans affecting the climate is that there is evidence that the climate of the earth has swung erratically many times. Human civilization developed when it seemed to settle down a bit. If we have another ice age, civilization as we know it is fucked.
Course, maybe *not* burning fossil fuels is going to cause a massive climate change (ie/ perhaps a greenhouse effect will delay the inevitable ice age). In which case, we're fucked.
Fucked if you do, fucked if you don't.
Fuck, eh?
(Damn, that was a gratuitous use of profanities... Kids, don't read this post!)
Re:Wrong (Score:2)
Or of course, we could atleast compensate and anticipate such drastic change in the global climate, instead of plodding along dumbfounded with our heads up our asses as anything we could possibly could do passes us by.
Re:Wrong (Score:1)
Re:Wrong (Score:1)
Re:Wrong (Score:1)
Re:Wrong (Score:1, Insightful)
Re-Read the thread and the parent you replied to. He is saying that even if we don't burn fossil fuels we might be on the verge of an ice age. If anything, burning fossil fuels might help warm the planet slightly and postpone the next ice age.
There are plenty of other reasons to bother but I feel the main one is because we created (with the help of our parents) this mess and just sitting idly by is just plain lazy and stupid.
Massive climate change has happened in the past without man's help. And some of those changes have been much more extreme than what we have witnessed in the last 150 years.
Complacency isn't an excuse it is a cop out.
No, but recognition of the immense power of mother nature and our miniscule importance IS.
Sorry I know I am going on a rant but my god people wake up and smell the CO2, do something about it, ride the bus, take a bike every little bit helps!
Every bus you take, every bike you ride contributes just that much more to quickening the next ice age.
I believe that dealing with a little extra heat in our enviroment is more manageable than dealing with ice a mile thick. YMMV.
Re:Wrong (Score:2)
Yes, and people die of natural causes so murder is ok huh?
Just because there have been other catastrophic climate changes and massive extinctions doesn't mean we are not causing this one and that we should just keep repeating our mistakes and let it happen or make it worse.
I believe that dealing with a little extra heat in our enviroment is more manageable than dealing with ice a mile thick. YMMV.
Say that to the next flood/hurricane/tornado that destroys your town.
We are not heading for an ice age. Sure, there seems to be an ice-age cycle and we would be approximatly due for a new one, but in geological terms, the error factor is of thousands of years. Plenty of time for civilisations to rise and fall. In the meantime, we have caused a hole in the ozone layer, we've made the planet way more radioactive than it was before, and we're buring the forest and even the fossilised forest really really fast. You think that's not a problem because it isn't in your own back yard, but we are doing it, its happening, and its dangerous. So we don't know exactly what will happen because nothing of this scale has ever been done before, but we do know that we are causing a climate change. How do we know? Because of rational thought, it goes like this: For every action there is a reaction of equal propostion. We are dumping megatons of climate changing pollutants. You expect that there will be no reaction to this? Do you also expect Santa to bring you gifts at Xmas?
Re:Wrong (Score:1)
The fact is, we truly DON'T know that we are causing it.
The temperature record of the last 150 years--even if you accept the one championed by the IPCC--is still definitely within the range of normal climate variance. That we happen to be on the upswing of the variance at the same time of the industrial revolution doesn't mean that the industrial revolution caused it.
Since the temperature record itself, being within the range of natural climate variation, does not provide any reason for alarm, we are left with climate theories. Exceptional claims require exceptional proof. So far, every time a climate model is made more accurate the result is less expected climate change.
In short, despite the hype, we've been given NO reason to believe that what we're witnessing is anything to be alarmed about.
I believe that dealing with a little extra heat in our enviroment is more manageable than dealing with ice a mile thick. YMMV.
Say that to the next flood/hurricane/tornado that destroys your town.
There is no proof that global warming--if it is happening--causes an increase in hurricanes or their strength. We have theories, but no proof.
In fact, this was supposed to be an "above average" hurricane season--and that "above average" rating was attributed, at the time, to global warming. They've already reduced their estimate of named storms once--I believe they were expecting 11 and are now estimating 9. And, if you haven't noticed, the second hurricane of the season just formed yesterday. We're way behind on our hurricane season this year.
In the meantime, we have caused a hole in the ozone layer
The ozone hole is naturally occuring and varies naturally. Sure, CFCs didn't help--but to say that we created the hole is wrong.
we've made the planet way more radioactive than it was before
Define "way more" radioactive? Perhaps a few areas where we've tested nuclear weapons, but do you have any evidence that on a global scale earth is more radioactive now than it was 100 years ago?
and we're buring the forest
Actually, we put out more naturally occuring fires every year than fires we create. As a result, our forests are denser than they were 50 years ago. Of course, this also means that when there is a fire there is a potential for more burning--but to say we're burning the forests is inaccurate.
and even the fossilised forest really really fast.
Uh huh. We were supposed to run out 2 years ago. But I guess the new number is 2030 or 2050 or so.
but we do know that we are causing a climate change. How do we know? Because of rational thought, it goes like this: For every action there is a reaction of equal propostion. We are dumping megatons of climate changing pollutants. You expect that there will be no reaction to this?
Unfortunately, the most logical of thought can often be wrong and disproved in the real world. Communism looks good on paper, too.
First, it's not megatons... it's gigatons.
Before worrying about the number of gigatons of CO2 produced by humans (6Gtons/year), consider how much CO2 is naturally occuring (over 144 Gtons/year). Further consider how many hundreds, thousands, or millions of gigatons of other gases (Nitrogen, Oxygen) exist in the atmosphere.
"Gigaatons" of CO2 sounds scary. But when you consider how much of CO2 is naturally occuring and how much is caused by humans, AND you consider the amount of atmosphere it is being mixed in to, it is inconsequential.
Start doing some research and don't just trust your own logic and what the popular media spoon feeds you.
Re:Wrong (Score:2, Insightful)
PS I walk to work. Is that OK?
Re:Wrong (Score:2)
What's with the constant notion that 'Our Children' will fix everything? Our children are no more likely to do anything than we are, and they aren't substantially smarter. So why not you get off your ass and do something to help? Maybe we could go for the novel concept of doing something about the problem ourselves instead of hopeing that someone in the future will fix the problem so we don't need to worry about it? Really, if everyone says, 'Our kids will fix it..' then who is going to fix it for real? Your parents probably thought the same thing about you too y'know.
Kintanon
Re:Wrong (Score:2)
Re:Wrong (Score:2)
The point of the troll is that a significant majority of environmentalists are proponents of the idea that nature can do no wrong and industrialized humanity can do no good.
Re:Wrong (Score:2)
But do they really believe this?
As far as I can tell, no important environmentalist makes this arguement.
Re:Wrong (Score:1)
Re:Wrong (Score:2, Insightful)
I read some of this in a page about paleography, but I don't find the link now
Earth has had warm and cool times. There were some times (like the ones the dinosaurs lived) of warm global temperature, reaching mid temperatures of 20. This means crocodiles (sp?) and palm trees near the poles, tropical humid weather all across the globe, etc.
And then there were the glacial periods, which we know a bit more: hairy rhinoceros, mammoths, snow a go-go, and that stuff. Man ("homo sapiens", I mean) appeared after one of these, IIRC.
The times of transition from one to another were usually marked by global extinctions and another funny events.
So, in my humble and not remotely knowledgeable opinion, global warming is caused by men *accelerating* a natural proccess, not *creating* it. It's bad anyway, but it's different
Re:Wrong (Score:1)
You missed the most important point. They haven't even proved that we are in a long term warming period. The computer models are about 60 degrees off in estimating temperatures in the upper antartic atmosphere.
Temperatures as recorded by satellites show no change above that suggested by the 11-year sun spot cycle.
So, we have evidence of no change recently, and massive evidence of great change in pre-history. From this you conclude that man is helping current change?
Now, please notice that I said 'evidence of no change', e.g. the satellite record, not 'no evidence of change', e.g. retreating deserts. The satellites record global temps, the deserts are a local (though large) thing.
Exactly! (Score:1)
Global warming is as real today was the next "ice age" was 20 years ago. Either is possible, neither is certain, and there's very little we can do about either.
The thing is, certain people who are used to knee-jerk reactions are trying to react in the same way to the climate. Political winds can change every few years, but the climate, in the grand scheme of things, is the same today as it was 20 years ago. The fact that some people are now talking about global warming reflects a knee-jerk reaction to events that happen on a geological timescale.
But these people aren't trying to make changes that would have any real effect on the planet and that's why they aren't even thinking on geological timescales. These people are trying to make political changes, which is why we see waffling from "ice age" to "global warming" in the span of about a decade (IIRC, they were still talking about ice age in 1980 and I believe global warming became hip around 1990?). It is also why their "solutions" are political (i.e., Kyoto), not scientific. Rather, they try to use science to justify and force political change.
I'm so sick of environmentalists trying to push their political agenda under the guise of environmentalism. The 9/11 attacks were awful, but if there is one good thing that has come out of the War on Terror it is that no-one has really cared about the whole "global warming" debate in about a year. It's been demoted to its proper level of importance. :)
Re:Exactly! (Score:2)
Rubbish. Can you name a single peer reviewed scientific paper from 20 years which mentions a ice age (not ones on long term global cooling). Whereas, the science of global warming has hundreds (maybe thousands) of scientific papers used in support of it.
but the climate, in the grand scheme of things, is the same today as it was 20 years ago. The fact that some people are now talking about global warming reflects a knee-jerk reaction to events that happen on a geological timescale.
Not true. The earth's surface is hotter than what it was 20 years ago.
The 9/11 attacks were awful, but if there is one good thing that has come out of the War on Terror it is that no-one has really cared about the whole "global warming" debate in about a year. It's been demoted to its proper level of importance.
Is the US news (assuming of course, that you are a American) incredibly different to the Australian news? Because global warming has been all over the Aussie media over the last year.
Re:Wrong (Score:2)
And your scientific peer reviewed evidence for this is?
So, we have evidence of no change recently,
Rubbish.
Land based tempertures have steadly increased over the last 50 years (by approx. 0.1 K/10 years). This increase is still noted when urban heat islands are taken into account.
Sea surface temperture has also steadly increased.
Deep sea measurements of ocean temperture have also shown a increase in temperture over time.
A increase in the infrared absorption spectra of the atmosphere has been observed.
Northern Hemisphere annual snow-cover extent (SCE) has decreased by approx. 10% since 1966, as observed by satellite.
Over the last 30 years the Northern Hemisphere sea-ice extent has also decreased.
The sea ice thickness in the Arctic was measured by military subs from the 50's to the 70's. When it was remeasured in the 90's, a large drop (approx. 40%) was observed.
Near surface perefrost in the Northern Hemisphere has also been observed dropping over time.
This is just a quick review of some indicators of temperture which all point towards a increase in surface tempertures.
and massive evidence of great change in pre-history.
The increase in temperture has been incrediblely quick when compared with past natural temperture changes.
From this you conclude that man is helping current change?
Him and the vast majority of the worlds climatical scientists.
Re:Wrong (Score:1)
Re:Wrong (Score:1)
Well, it would seem that if we can get enough space junk in orbit around the earth we can effectively block out part of the suns rays and counter act global warming, which is currently only recognized by non-Americans...
Ring around the planet? (Score:3, Interesting)
Seriously, though, does anyone else seem to notice that we only notice problems when scientists discover an explanation for it? We were polluting like mad, and then scientists discovered the ozone layer was being depleted, and we suddenly "noticed" global warning. People were smoking like chimneys, and scientists discovered that what is in cigarettes causes someone with a genetic predisposition for cancer to generate tumors, and we suddenly "noticed" that people who smoked lived a little bit shorter lives.
I'm not intending to say that ignorance is bliss, but sometimes, it seems that way.
Now if you'll excuse me, I'm going to go have unprotected sex with this person over here, or has science found out something about that recently...[grin]
Well,as an environmentalist (Score:2, Funny)
We've got to do it for the children.STOP THE RINGS AROUND THE EARTH BEFORE ITS TOO LATE.After all look at saturn,theres no life there.Coincidence?I think not!
Re:Ring around the planet? (Score:3, Informative)
Did it reverse aging? (Score:1)
Repost from Tuesday (Score:5, Informative)
Re:Repost from Tuesday (OT) (Score:2, Offtopic)
Re:I wonder if comments like these will pop up (Score:1)
Re:I wonder if comments like these will pop up (Score:1)
Re:Thanks (Score:2, Informative)
Dinosuars are in the Bible. [clarifying...ianity.com]
Re:whoa (Score:3, Informative)
Or I could be trying to do astronomy in my head right after I woke up.
Oh well... (Score:1)
rings and gravity and stuff (Score:2, Insightful)
But I thought it was an interesting post at the time & I'd love to see it get modded up 'cause the resulting conversation between some of the even less cluefull here I would find entertaining.
Re:rings and gravity and stuff (Score:2)
OK, I am NOT a physicist. I don't what I'm talking about. But I figure
someone here can tell me how I am wrong.
This is my silly little theory:
Given that:
1. Large planets have rings systems that rotate along the equatorial plane
of the planet.
2. Stars have planets that rotate along the equatorial plane of the star.
3. Galaxies have stars that rotate along *something*, and this something
might be a black hole.
Could it be a reasonable explanation that:
1. The very act of mass (especially a large mass) *spinning* has a
gravatational effect.
2. These effects intensivy as mass increases and as the rate of spinning
increases.
3. As the rate of spinning increases, the gravitational effect, whatever it
is, increases. Furthermore, as the rate of spin approaches the
speed of light, this effect becomes very large.
4. One of the properties of this effect is that it causes dust rings to
form around large spinning planets, planets to orbit around large spinning
stars in a plane, and stars to form into a galactic plane around large
spinning black holes.
And then, if that is a reasonable explanation, could we then:
1. By looking at the mass of the rings in relation to a large spinning
planet, come up with a good estimate at the rate of spin and/or
the mass of a black hole at the center of a galaxy?
2. Maybe star clusters (those are galaxies without a plane, right?) are
around stationary black holes?
Please feel free to tear my quaint little amateur theory apart. Thanks!!
--io333
Which was followed up by (myself):
Oh yea, two more questions:
If this effect is exists, what in the world happens if you take a small
sphere and spin it at the speed of light (well just below it of course)?
And again, if the effect exists, what does that mean about all of the
teeny particles that make up all matter spinning really fast in
random orientations? It certainly wouldn't be the *cause* of gravity,
right?
Re:rings and gravity and stuff (Score:2)
Re:rings and gravity and stuff (Score:1)
Re:rings and gravity and stuff (Score:1)
So... (Score:2, Redundant)
I guess that's one way to get published.
Re:So... (Score:1)
Is it supposed to be "In Googlum non est, erat non est"?
Climate change forced human evolution (Score:1)
in the evolution of our own species,
and the ring glaciation theory makes sense.
At some time in the past Africa became too
cool to sustain the animals we hunted...
they migrated north and into Asia
and we were forced to follow.
The timing is not right... humans evolved about 1-3m years ago
but this is a lot closer than 65m years since the last 'Big Strike'
Billy Mays (Score:3, Funny)
heh... (Score:1, Funny)
about skepticism (Score:5, Insightful)
ALL scientists are skeptical. It's a basic requirement of the scientific method, and a reason it works wso damn well.
Re:about skepticism (Score:3, Insightful)
The sad fact is that scientists are human. They have their own allegiances -- not always to the scientific method. Some are quite petty.
"a new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it"
--Max Planck
Thomas Kuhn had a lot to say about this. Learn more here [harvard.edu].
Re:about skepticism (Score:1)
In a perfect world. Unfortunately, many of the "scientists" that advocate global warming punch a hole in that theory. Either they aren't scientists or they aren't sufficiently skeptical. It's a toss-up as to which is the case. And the fact that these people aren't sufficiently skeptical and, thus, fail the test of the scientific method is why their theories and conclusions are prime material for tabloids.
The sad part is that since they are supposedly scientists and people ASSUME the scientific method is being followed they get reported as news. Sad.
Re:about skepticism (Score:1)
Couple that with the undisputed fact that CO2 increases due to fossil fuel burning have been measured for a long time (the Keeling curve, e.g. these plots [pbs.org]) Now, throw in the physics of radiative transfer to see how increases in CO2 trap IR radiation and hence increase temperatures, and I'd say you have a pretty strong case. You have a plausible mechanism, observations of the putative cause, and observations of the effect.
I think at this point it's harder to come up with a mechanism why we wouldn't be causing global warming; you have to explain a) why the observed human-caused CO2 increase doesn't cause a net heating, while at the same time b) you have to come up with a reason for the system to still show some warming from "natural" causes. Warming that is very different (in that it is very rapid) from what is seen is climate records of the past. Oh, and you also have to explain why your point of view isn't at all influenced by financial interests in maintaining the status quo (remember, scientists working on global warming don't get paid to cry wolf - if anything they'd get more research funds if they could provide a soothing reassurance that there is no global warming).
It is true that the climate is variable and complex, and that we are only beginning to understand it well. It is also true that scientific opinion changes as new data, theories and people get involved. However, the point of science (as opposed to pretty much any other intellectual activity) is that it eventually converges toward the right answer. That is often a long, painful process - but I think we can be confident that we understand climate better now than we did in the 70's. Unfortunately the answers we are finding makes a lot of people uncomfortable. But instead of "shooting the messenger" (by trying to discredit the scientists), wouldn't it be wiser to try and deal with reality as it is?
Re:about skepticism (Score:1)
The fact is, the CO2 produced by humans is a fraction of the total amount of CO2 produced by nature. I don't dispute that we generate CO2. I dispute that it makes a difference. Our CO2 production is far overwhelmed by nature's CO2 production.
a) why the observed human-caused CO2 increase doesn't cause a net heating,
Oh, I'm sure it might produce some net heating. But when you analyze the numbers you will realize that the amount of CO2 we're generating is miniscule compared to what's there naturally. I don't dispute that there could be some net heating. I DO dispute that it's significant, and definitely disagree with the doomsday scenarios that many environmentalists predict our actions will create.
b) you have to come up with a reason for the system to still show some warming from "natural" causes.
No, you don't have to come up with a reason for the system to show natural warming. That's the problem, you're thinking backwards. Those claiming that the warming is anything but natural need to provide some convincing evidence. Otherwise there is NO reason to believe it is anything but natural.
Warming that is very different (in that it is very rapid) from what is seen is climate records of the past.
Check your climate record. There have been very sudden movements in both directions in the past. There is nothing particularly special about this one except that we are here to witness it.
Oh, and you also have to explain why your point of view isn't at all influenced by financial interests in maintaining the status quo (remember, scientists working on global warming don't get paid to cry wolf - if anything they'd get more research funds if they could provide a soothing reassurance that there is no global warming).
Excuse me, but reality check: Most scientists that study global warming on a full-time basis do so because of funding. The funding can come from oil companies or the funding can come from environmental groups, universities, or the government itself. As soon as these researchers say, "No, there is no evidence of global warming" their research budgets dry up.
To pretend that those scientists that are promoting the theory of global warming have absolutely no financial interest in the results and are any more professional or ethical than those paid for by oil companies is very, very naive.
However, the point of science (as opposed to pretty much any other intellectual activity) is that it eventually converges toward the right answer.
The problem is that there are politicians out there advocating drastic changes in our social, political, and economic systems based on partial, in-progress results.
Another problem is that the scientists themselves are telling us (the world AND the politicians) what we need to do. That's not science, that's politics. The scientists should research climate and publish their results, and the results should speak for themselves. Leave it to society and the politicians to draw a conclusion of a reasonable course of action.
Scientists are the "clergy" of the 21st century. When "scientists" start making policy we will again have a theocracy that the "separation of church and state" was supposed to protect us from. Just now the clergy will be made up of "scientists" rather than religious people. The political result is the same.
Re:about skepticism (Score:2, Informative)
They why do we see a steady rise in the level of atmospheric CO2 over the last 50 years, an increase that is about what we'd expect based on the amount of fossil fuel burning, etc? (Again, the Keeling curve). Natural CO2 releases may be larger, but if they are in equilibrium with CO2 sinks, even a small increase in net CO2 input can cause a steady rise in atmospheric CO2 levels. (At least until the sinks catch up, which takes time, and may not occur at all). Either way, we are seeing an increase, and isotopic signatures show that the carbon comes from fossil fuels (no C12).
Another way to make the point: look closely at the Keeling curve and you will see small variations that are in sync with the seasons. This is telling you that natural changes in CO2 respiration exist, are measurable, and are smaller than the large human-induced trend. In raw numbers, humans dump about 6Gt (gigatons of Carbon) per year into the atmosphere. The biosphere absorbs about half of that, the rest stays in the air.
I don't dispute that there could be some net heating. I DO dispute that it's significant
Well, there are several groups that have made estimates of the heating. As I recall it will likely be between 0.5 and 6 degrees (C) in the next century, with a peak in the probability function around 1-2. That is a larger increase than in other interglacial times, and it puts us in a climate regime that we haven't been in for at least a few million years (high CO2, warm. The typical situation has been colder with less CO2). We can argue a lot about detailed effects, but the climate will be different from now. There are a lot of models that suggest shifts in agriculture, and sea level rise. They may not be a problem for some rich guy in Colorado, but it will be a serious problem for Bangladesh (they have many). Of course, if you don't care about Bangladesh, fine. But keep releasing CO2 and in the next century it will be a problem for Florida.
No, you don't have to come up with a reason for the system to show natural warming .
If you accept that we are causing an increase in CO2, and you accept the physics of IR absorbption, my argument stands - why is the warming we see NOT due to the CO2 we release?
There have been very sudden movements in both directions in the past
For climate records such as ice cores it is often impossible to get good time resolution - so you can't tell the difference between an instantaneous rise and one that takes 2000 years. The rise in the past century is at least as rapid as any we have seen, and faster than most. Also, there may have been climate change, but nothing says it didn't have serious effects on life at the time. There have been large species die-offs related to climate change in the past. If anything, this reinfoces the point that it may be hazardous to jolt the climate severely. maybe not in terms of wiping out all life on the planet, but certainly in terms of causing e.g. agricultural disruption.
To pretend that those scientists that are promoting the theory of global warming have absolutely no financial interest in the results and are any more professional or ethical than those paid for by oil companies is very, very naive.
I don't know about that. There tends to be an extra layer of insulation between government-funded scientists (who by and large worry about global warming) and the financial interests. Certainly with the current U.S. administration there is no incentive for government scientists to exaggerate the seriousness of global warming.
The problem is that there are politicians out there advocating drastic changes in our social, political, and economic systems based on partial, in-progress results.
Actually, they seem to be advocating small changes in how we produce and consume energy, changes that will likely have to be made sooner or later anyway (we can't go on burning oil this inefficiently forever). In fact, dealing with global warming may well stimulate innovation and help the economy. After all, improving energy efficiency make the economy work better. The converse is certainly true - look at the former Soviet Union for an example of what can happen to a wasteful industrial economy.
Another problem is that the scientists themselves are telling us (the world AND the politicians) what we need to do. That's not science, that's politics.
Since when does the mere fact that someone is a scientist disqualify him or her from making policy recommendations? After all, in the U.S. every idiot is entitled to an opinion, logical or not. If someone who is intelligent and well-educated spends a lot of time studying a problem and comes to the conclusion that action is needed, why should we ignore that persons opinion? I know anti-intellectualism is alive and well in the states, but that doesn't make it wise.
Scientists are the "clergy" of the 21st century. When "scientists" start making policy we will again have a theocracy that the "separation of church and state" was supposed to protect us from. Just now the clergy will be made up of "scientists" rather than religious people. The political result is the same.
Now this is a lovely topic for a long discussion, but I have to get back to work. However, I will say this: there is a big difference between science and religion. Religion claims to have a monopoly on the truth, and hence once the Pope or the Mullah or clergy or whatever has spoken (as the mouthpiece of God, of course) there can be no argument. Science, when it works properly, is always ready to admit error. That makes it possible to improve science. Why does this matter? Well, it makes for a big difference in the political end result: a theocracy burns dissenters at the stake. A democracy with engaged scientists has a fruitful, ongoing debate. Also, with scientists involved in the debate you can actually get informed opinions. Otherwise it's just a big gab-fest ,i.e. slashdot.
Re:about skepticism (Score:1)
I would submit that, there, you are using the "fear factor" by suggesting that the sinks may not catch up at all. Sure, anything is possible. But if there is one thing that is constant in earth's history, it's change. That's especially true for the climate. To suggest that, for the first time, the earth will not be able to establish a new equilibrium seems rather fatalistic and not based on any historic precedent. If the earth was able to recover from planet-killer asteroids, I think it will be able to establish a new equilibrium with its current habitants.
In raw numbers, humans dump about 6Gt (gigatons of Carbon) per year into the atmosphere. The biosphere absorbs about half of that, the rest stays in the air.
Which, over years or decades, will probably lead to more sinks in order to consume that. It's not like we're producing poison. Ok, well, some of what we produce is poisonous, but CO2 is always trumpted as the main cause of global warming. But CO2 isn't itself poison: It is food that can and almost definitely will stimulate the organisms that feed off it. Which will produce more oxygen. Certainly equilibrium will be established.
We can argue a lot about detailed effects, but the climate will be different from now.
Can you show me some point in time in the climate record where the climate remained static for more than about, oh, 5 seconds?
Sure, the climate will change. The climate will change regardless of what we do or don't do. It may change in different ways, but we can't even be sure of HOW it will differ given two courses of action. If we can't say with any certainty how the climate will react to any of several scenarios, how can we honestly state that one is worse than the other?
There are a lot of models that suggest shifts in agriculture, and sea level rise. They may not be a problem for some rich guy in Colorado, but it will be a serious problem for Bangladesh (they have many).
First, all models have shown is that the more they improve them, the less global warming is expected.
Second, it is not even proven whether global warming will cause sea levels to rise. Most of the sea level rise would have to come from Antartica--and the temperature could rise 10 degrees and that ice wouldn't melt.
And if it did happen to melt and sea level did rise, who is to say that earth doesn't want to go into an ice age and only our CO2 production is avoiding it? Given the choice between relocating 131 million people in Bangladesh or relocating around a billion people if mile-thick ice came pushing down from the north over North America, Europe, and central Asia, I'll take the former.
I insist that it is easier to deal with a few degree increase in temperature, a few meters increase in sea level, than ice a mile thick.
I don't know about that. There tends to be an extra layer of insulation between government-funded scientists (who by and large worry about global warming) and the financial interests. Certainly with the current U.S. administration there is no incentive for government scientists to exaggerate the seriousness of global warming.
The fact is, the individual scientists are not appointed by the administration. They've worked there for years, decades. I'm also not talking so much about those scientists hired full-time by the government, but rather those that get funding grants. Here's a great example [cnn.com] that just came out today. This was funded by NASA. If these institutions came out and said, "No, nothing to see here" and a few more studies produced similar responses, do you think NASA is going to continue funding these types of research?
Actually, they seem to be advocating small changes in how we produce and consume energy, changes that will likely have to be made sooner or later anyway
The rational ones, perhaps. But what we see on the news and in politics are the ones that advocate 6-8% reductions in CO2 production from 1990 levels while offering exemptions to India and China, where the now famous Asian cloud of pollution is literally killing millions. That is not a "small" change, nor is it likely to help the earth's environment. It'll just make developed countries cleaner and kill a few million more Asians per year.
Honestly, I'm not sure where those in favor of Kyoto are 1) trying to achieve a distribution of wealth from the richer to poorer countries, or 2) export the pollution of richer countries to the poorer countries. Either way, I'm opposed to the end result.
After all, improving energy efficiency make the economy work better
I agree, let's improve efficiency. But let's work with what we have. Going cold turkey on carbon fuels--a course of action virtually required if we are to meet CO2 goals called "essential" by some scientists--is not an option right now. Rather than spending so much time and money investigating the effect of carbon fuels I'd love to see that money going into looking for cleaner solutions. That'd be a more effective use of resources.
Since when does the mere fact that someone is a scientist disqualify him or her from making policy recommendations?
Oh, he's entitled to his opinion. But, as a professional, he should make every effort possible to separate his personal opinions and science.
Science, when it works properly, is always ready to admit error.
When it works properly. But if you compare the science of astronomy to the climate science the difference is truly shocking. We are constantly reading about new discoveries, changes to old thoughts in astronomy because of some new pulsar they found, etc. It bounces all over. When it comes to climate science, all we hear is how the earth is warming and we are at fault with an impressive level of certainty expressed when you consider it is all based on models that, whenever "improved," inevitably produce lower estimates of global warming and which aren't even able to produce our current climate based on inputs from 150 years ago. Now, you can choose to conclude that we only hear about us causing global warming because it's true. But do you really think there is no proof of the opposite? Do you really think most of these funded scientists do the research wondering what they'll find? Perhaps, but I'm skeptical.
I truly believe most of them already know the results they're looking for (i.e. what they already believe or what will keep research dollars flowing) and either look for results that confirm that, or simply don't report things they find that are not convenient to publish. As you said, they're human too and, as such, not completely disinterested in the results.
Well, it makes for a big difference in the political end result: a theocracy burns dissenters at the stake
And in the current environment, a series of reports saying that nothing serious is happening in the environment would cause a lack of research funding. Those scientists that disagree with those that promote global warming are ridiculed or written off as having been "purchased" by oil interests. Sure, they're still alive, but they are burned at the stake in terms of funding and reputation in their field.
Re:about skepticism (Score:1)
I would submit that, there, you are using the "fear factor" by suggesting that the sinks may not catch up at all.
OK - they will catch up at some point. The issue is where is that point? A degree and 100 years? 10 degrees and 1000 years? Or is the new equilibrium point similar to Venus? The runaway greenhouse effect is an extreme (and not seriously contemplated, I should add) possibility, since we have no proof that the climate is inherently stable to all perturbations - in fact likely it isn't. I'm not trying to up the "fear factor", but I am saying that it's not clear to anyone if/when/how the system will reestablish equilibrium after we double or triple atmospheric CO2 levels. An interesting example is that of North American forests - which were long touted as big carbon sinks. Well, now big forest fires are starting to return that carbon into the atmosphere.
In short, the Earth will establish equilibrium. Whether that includes a large human population is open to debate - it certainly doesn't include large dinosaur populations. The point being that climate change has in the past wiped out species.
Sure, the climate will change. The climate will change regardless of what we do or don't do. It may change in different ways, but we can't even be sure of HOW it will differ given two courses of action. If we can't say with any certainty how the climate will react to any of several scenarios, how can we honestly state that one is worse than the other?
It's amusing that our debate is mirroring the larger one of the past few decades. First it was "There is no warming", followed by "So there is warming. But it's insignificant". Then it's "nobody really knows who's fault it is". Next you'll probably say either that we have to study the problem more before we act, or that the evil Chinese should act first since in the years to come they will produce more CO2.
What we can say is that we are perturbing the climate system in a way that it hasn't seen before, and with a very large perturbation (doubling or tripling CO2 in 200 years is a large, rapid change). Something will happen, and the best models seem to indicate rather unpleasant effects.
First, all models have shown is that the more they improve them, the less global warming is expected.
Do you have proof of this statement? I can recall a few announcements in the last couple of years where the estimates were revised upward, but it'll take time to find the references. In fact, the IPCC 2000 report (which is effectivly a summary of many, many models), revised their estimate upward from 1995. So I don't think your statement is true.
Second, it is not even proven whether global warming will cause sea levels to rise. Most of the sea level rise would have to come from Antartica--and the temperature could rise 10 degrees and that ice wouldn't melt.
That too is debatable. I take it you are referring to the West Antarctice ice sheet? There was a recent article in Science talking about how recent observations of ice dynamics (e.g. the recent Ross (?) ice shelf collapse) that seem to indicate that ice sheets can collapse very quickly with only small perturbations. Besides, the debate as I understand it is whether the West Antarctic Ice Shelf will go after a 5 degree rise - 10 degrees will almost certainly take it out. That gives you 10 meters of sea level rise right there. (On the upside, though, we wouldn't have to hear more about bungled elections in Miami)
And if it did happen to melt and sea level did rise, who is to say that earth doesn't want to go into an ice age and only our CO2 production is avoiding it?
And what is to say that tomorrow we won't be invaded by large green two-penised^H^H^H^H headed aliens that just happen to be allergic to CO2, thus having Exxon save the day? Seriously though, folks, if models and observations start indicating that is happening, we'll deal with it then. In the mean time, we shouldn't use such specious arguments to avoid dealing with a better known threat.
I agree, let's improve efficiency. But let's work with what we have. Going cold turkey on carbon fuels--a course of action virtually required if we are to meet CO2 goals called "essential" by some scientists--is not an option right now.
Will it ever be? I think we could do more than we are, and we won't have viable alternatives until we start investing enough to bootstrap new technologies. In fact, very few modern technologies have been adpoted without large amount of initial government subsidy. The Internet (how many years of government funding?) and even the car (the Interstate system was a huge subsidy) are examples.
But if you compare the science of astronomy to the climate science the difference is truly shocking. We are constantly reading about new discoveries, changes to old thoughts in astronomy because of some new pulsar they found, etc. It bounces all over. When it comes to climate science, all we hear is how the earth is warming and we are at fault with an impressive level of certainty
Are you an astronomer by any chance? There are certain things most astronomers will state with "impressive certainty", like the fact that the Earth is round, or that the universe started in a Big Bang, or what the production rate of solar neutrinos is (which depends on some really fiendishly complex models, yet we are so certain of it that we invented new physics (netrino mixing) to explain. Later verified by observation, I should add. )
We hear about global warming because it is an observational fact, physically plausible, and of some concern globally. There is no vast conspiracy to "conceal the truth", intentional or not.
Those scientists that disagree with those that promote global warming are ridiculed or written off as having been "purchased" by oil interests. Sure, they're still alive, but they are burned at the stake in terms of funding and reputation in their field.
I don't know about that - S Fred Singer is still around and keeps getting invited to seminars here. If a scientist is right, sooner or later scientific opinion will come around to his point of view. It may take a LONG time, but the point of science is that it happens faster than with the alternatives (i.e. never).
Re:about skepticism (Score:1)
Hey, it's Friday, don't sweat it. :)
OK - they will catch up at some point. The issue is where is that point? A degree and 100 years? 10 degrees and 1000 years? Or is the new equilibrium point similar to Venus?
I agree we don't know. It would seem logical, however, that considering the 6Gt of carbon we're adding to the environment is arguably less than 2% of the total produced (and consumed) by nature each year that the answer is most likely yes, and that it would tend to be on the lower side. Do I have facts to back that up? No, I don't.
What I would agree is that we should watch our carbon sinks. If we produce 6Gt to the atmosphere each year AND destroy carbon sinks I can admit to a problem. In that case I think the best solution would be to reduce destruction of the sinks since they're usually pretty and pleasant to camp in anyway.
An interesting example is that of North American forests - which were long touted as big carbon sinks. Well, now big forest fires are starting to return that carbon into the atmosphere.
And, *presto*, equilibrium. The problem, of course, is we started putting out forest fires which caused too much undergrowth in the forests. So when they burn now, they burn bad. The forests are still carbon sinks--granted, reduced in effectiveness until they regrow--but that is part of the natural cycle.
In short, the Earth will establish equilibrium. Whether that includes a large human population is open to debate - it certainly doesn't include large dinosaur populations. The point being that climate change has in the past wiped out species.
I don't think it is arrogant to say that we can adapt a little better than the dinosaurs.
Besides, I've heard certain evironmentalists say that we "need" to get to a 2 billion population which is suposedly sustainable. They've never said how they'd like to accomplish that. Perhaps a nice climate change to par down the population is just what we need. [I am being sarcastic, just in case it wasn't obvious].
Next you'll probably say either that we have to study the problem more before we act, or that the evil Chinese should act first since in the years to come they will produce more CO2.
Do I think we should improve fuel efficiency of cars? Yes. Do I think we ought to investigate solar power? Yes. Do I think we ought to use more nuclear energy which, when done right, is comparably clean? Yes. Do I think it's a good idea to turn off the lights when you're not using them? Yes.
Do I think we need mandatory caps on CO2 production? No. Do I think the developed world should reduce CO2 production while India and China, making up 2 billion people, are exempt? No.
So I will agree to a rational, measured response based on what we know now. But don't ask me to agree to massive social, political, or economic changes based on what we know now. We don't know enough. In that sense, YES, we need more research first.
Something will happen, and the best models seem to indicate rather unpleasant effects.
Perhaps, although the best models indicate less unpleasantness every time they are improved. With each improvement, the amount of unpleasantness approaches zero.
Do you have proof of this statement? I can recall a few announcements in the last couple of years where the estimates were revised upward, but it'll take time to find the references. In fact, the IPCC 2000 report (which is effectivly a summary of many, many models), revised their estimate upward from 1995. So I don't think your statement is true.
It is true, but I'd also have to go back and search for the references. I don't doubt that the IPCC revises their estimates upwards, they are a reactive group trying to stimulate action. It would be counterproductive to revise them downwards. But I have read quite a few stories since 1990, initially in newspapers and over the last few years, where the estimates have been revised downwards. I'll grant they don't get as much media attention.
I'll try to go back and find some links for ya.
That too is debatable. I take it you are referring to the West Antarctice ice sheet? There was a recent article in Science talking about how recent observations of ice dynamics (e.g. the recent Ross (?) ice shelf collapse) that seem to indicate that ice sheets can collapse very quickly with only small perturbations.
Again, I'd have to go back to the source to verify names. I'm not good with names unless I note them down--but I do remember text that said that the vast majority of ice in Antartica is built 2 miles thick on top of solid land. That ice isn't going anywhere--in fact, if anything it only gets thicker.
As for ice shelves, they come and go.
Seriously though, folks, if models and observations start indicating that is happening, we'll deal with it then. In the mean time, we shouldn't use such specious arguments to avoid dealing with a better known threat.
You see, you're being as open-minded as scientists that think they have the answer before they conduct the experiment. We're due for an ice age, in the 70's we were supposed to be on the verge of the ice age. Suddenly we're dealing with global warming??
I'm sorry, but as much as the thought of using CO2 production to avoid an ice age sounds like science fiction to you, so does global warming based on the miniscule amounts of CO2 we're producing sound like science fiction to me. If we can cause global warming by producing CO2, what is so far-feteched about that avoiding an ice age??
I think we could do more than we are, and we won't have viable alternatives until we start investing enough to bootstrap new technologies. In fact, very few modern technologies have been adpoted without large amount of initial government subsidy.
So let's subsidize them! I'm all for developing cleaner and cheaper energy, and I'd much rather spend my tax dollars researching new energy than paying scientists to come up with more doomsday predictions. Rather than spending money on predicting what might happen, why not spend the money on coming up with a solution that makes the other predictions completely irrelevant?
We hear about global warming because it is an observational fact, physically plausible, and of some concern globally. There is no vast conspiracy to "conceal the truth", intentional or not.
I'm not saying there is a vast conspiracy. I think it is a self-feeding phenomenon that many scientists cling too for funding and many politicians cling to for power grabs or furthering their personal visions for the world.
I think Kyoto is a perfect example of that. Will you agree that if you slap CO2 limits on developed countries but exempt developing countries that you will not reduce pollution, just move the sources of pollution to the developing countries? Given that, what was the purpose of Kyoto? Either to move the pollution out of our backyard into someone elses, or move our jobs to developing countries (wealth redistribution). But you will NOT improve the worldwide environment. So what was the point of Kyoto?
If a scientist is right, sooner or later scientific opinion will come around to his point of view. It may take a LONG time, but the point of science is that it happens faster than with the alternatives (i.e. never).
The same can be said for religion, historically.
What happened to the debris? (Score:2)
Re:What happened to the debris? (Score:3, Interesting)
Here's the real scoop... (Score:3, Funny)
Tom
Uranus has rings! (Score:3, Funny)
Uranus is a gas giant, filled with methane and many toxic gases. Uranus is blue. Uranus has rings. As you can see, Uranus is full of surprises!
Try reading that to a kid with a straight face!
Re:Uranus has rings! (Score:2)
Re:Uranus has rings! (Score:1)
Re:Uranus has rings! (Score:1)
Can I be skeptical, too? (Score:4, Insightful)
So most of the rocks from such a collision will either be on an escape trajectory to become interplanteary debris, or secondary meterites that will fall over the next few days.
Where's the circularizing force in these models to put debris into long-term stable orbits?
Re:Can I be skeptical, too? (Score:5, Informative)
Unless something acts on it near apogee to circularize its orbit, that orbit will return to the point it began (which lies inside the atmosphere)
No. The model of orbital mechanics that you are using does not contain enough objects. Here is a more realistic way of visualizing the process:
Instead of looking at one chunk of rock in a billiard-like model, think in terms of the spray of material that would be generated by a glancing strike (which is also the most likely kind). Most of the particles in this spray will not have orbital velocity and will rain back down, with the larger and faster ones making a string of secondary impact craters. A much smaller portion will reach escape velocity and become interplanetary objects.
But what is significant is the group of particles whose velocities exceed orbital velocity but do not reach escape velocity. That is a pretty wide range of speeds. At first these objects will also have a wide range of apogees and perigees, but they will mostly be in the same plane. Their own gravitational interactions and collisions will redistribute the kinetic energy of the group as a whole into a ring. In essence, the circularizing agent that you are looking for is the aggregate effect of the group on each individual member, a sort of gravitational peer pressure. Ring formation is probably a positive feedback process, where the proto ring's growth increases its influence on the remaining wild particles.
There are three ring shepherds that will cause any debris ring (any satellite for that matter) to seek an equatorial orbit over time: the Sun, the Moon, and the Earth's equatorial bulge. I imagine the Moon's presence would also assure that any Earth ring would be relatively short lived.
I would also think that any Earth ring formed in this way would be quite bright, at least for a while. I would think the ejecta stream would suck along a lot of air and water vapor through entrainment, and that many of the ring particles would be frosted as they cooled.
I'm not saying I'm convinced that this happened. But it is an intriguing scenario and might go far to explain ice ages and such. One of the more intriguing things about it is that it appears to be testable in several different ways.
Re:Can I be skeptical, too? (Score:2)
What you describe is plausible for large amounts of ejecta (ala the "Big Whack" that is the current favorite moon formation theory). But the mutual gravitation of the amount of ejecta to be expected by even dinosaur-killer class impacts seems like too small a force to regularize an orbit in a single oribital period.
Lunar sheparding is an intriguing possibility, but orbits that get too near the region of earth-moon equigravitation tend to be chaotically unstable on periods of years -- most of the pieces of the Apollo project on such orbits have since lost them.
Until I see some n-body simulations, this seems like a neat idea, but one too implausible to account for what seems like a fairly common climatological anomaly. It's easy to think of orbital mechanics situations that seem neat and capture the mind, but just don't work (The Ringword is unstable, the Ringworld is unstable. Did the best that he was able, and it's good enough for me...)
Re:Can I be skeptical, too? (Score:1)
First, as you mention, you have to get this "ring" into orbit. I can see a big impact launching a few rocks into space that might be lucky and stay in abort. But thousands or millions of rocks to form a ring? Seems very unlikely.
Second, assuming there was a ring, how huge and dense would it have to be to really make a difference, even at the equator?
Try this: Hold a pencil about a foot off the ground on a sunny day and you'll see a shadow. Raise that pencil to an altitude of, say, 1000 feet and you won't see any shadow at all. Likewise, if you have a non-solid ring of small debris circling the earth at, say, 1000-24,000 miles there will be no effect. Certainly nothing that could effect the climate.
The world will be much better off when climate scientists realize (or acknowledge) that the earth's climate has, and will continue, to change all by itself due to changes in the sun's output and climate mechanics far more complex than a silly ring around the planet. The earth's climate is fundamentally STABLE. When it gets too cold, it warms up. When it gets too warm, it cools down. This has happened for eons without any assistance from the human race. We'd have to be arrogant to think that we are so much the center of the universe (or our planet) as to think we can affect this, for better or for worse.
Of course, climate scientists can't accept the possibility that the climate just changes. That would undermine their theory that humans are causing global warming. If it is established and accepted that wide swings in earth's climate are possible without any specific cause, then no-one will listen to them on global warming. Which would be good, but is why we constantly hear some new theory of how something affected/affects the climate.
Re:Can I be skeptical, too? (Score:2)
Okay, now try this thought experiment. Hold a length of window screen an inch off the ground. If it is close enough to the ground you will see the individual wires. Now raise that screen up a yard or two. The shadows of the individual wires will fade away. But you will still have a shadow the shape of the screen. Raise that window screen the 1000 feet you mention, you won't be able to detect the drop in insolation it causes. But tell me, if the window screen was a couple of square miles in area, do you think the drop in insolation would still be undetectable?
It seems to me the smaller the particle size the greater its ability to block or reflect light. Wouldn't you agree?
Proof by assertion? Cab you do the math to prove this assertion? Exceot I want you to assume the average particle size is 0.01 millimetres, not the size of a pencil, okay?Re:Can I be skeptical, too? (Score:1)
A window screen a couple of square miles just 1000 feet above the ground, sure, it would be detectable. But you're now putting true ring dimensions at 1000 feet elevation as opposed to their true elevations.
To give you an idea, you have to go to Saturn Ring G [nasa.gov] at 165,000km from Saturn's center before you get a ring more than 0.1-1km in "thickness." And that's for Saturn. For earth, I'm quite certain the ring would be on a smaller scale than Saturn. And 0.1km-1km at anything more than a few hundred miles is going to be more like the pencil at 1000ft than the huge window screen at 1000ft.
It seems to me the smaller the particle size the greater its ability to block or reflect light. Wouldn't you agree?
Certainly it would depend on the quantity of small particles. The article [cnn.com] says "a halo of boulders and rocks would compress around the equator into a thin plane." No mention of dust. I would think that makes sense since a meteor impact on Earth would result in most of the dust staying in the atmosphere since it would be quickly slowed down by the atmosphere given the small particle size, while larger rocks and boulders might make it to orbit. I doubt you'd find much 0.01mm particles in orbit, at least from a meteor impact.
The article also reads: "Boslough, a physicist at the Sandia National Lab in Albuquerque, and colleague Peter Fawcett, an Earth sciences professor at the University of New Mexico, devised a climate model to predict the effects of such a disk." Gotta love those climate models of scenarios that are impossible to compare to reality. Heck, the climate models have been SO accurate so far as far as global warming goes, why not duplicate their success with a climate model of something completely impossible to compare with reality to validate the model.
The article also says: "Under certain conditions, if the angle and mechanics are just right, a big asteroid or comet could create a debris ring by slamming into Earth, scientists theorize." So under certain conditions when the angle and mechanics are just right, we MIGHT get a ring. And that ring MIGHT have an effect depending on its characteristics. And if it has an effect, it MIGHT be detectable.
I would tend to believe that this guy was nearing the end of his research dollars and had to produce something, even if just a theory, in order to justify the research dollars he had received and maybe to score some more. It's always a bummer to receive funds, spend them over the course of a few years, and have nothing to show to the people that funded you.
Re:Can I be skeptical, too? (Score:1)
But the rings are very "wide", of the Sun isn't exctly above the equator the projected shadow will depend on how wide the ring is - potentially 1000's of kms.If the ring is even close to optically thick (i.e. blocks light going through it), it may potentially reduce incoming sunlight noticeably (a few percent is a big effect). If it has any dust it can likely be optically thick. Work out how many 0.1-mm particles you can make from one 10 km asteroid (10^21) then work out how much surface area they have (10^16 m^2). That's a pretty large sunshade.
For earth, I'm quite certain the ring would be on a smaller scale than Saturn.
More proof by assertion?
No mention of dust. I would think that makes sense since a meteor impact on Earth would result in most of the dust staying in the atmosphere since it would be quickly slowed down by the atmosphere given the small particle size, while larger rocks and boulders might make it to orbit. I doubt you'd find much 0.01mm particles in orbit, at least from a meteor impact.
Interesting point, but check out one of the above comments discussing how the ring is formed. In order to end up with a circular ring in the equatorial plane you likely need a lot of collisions between the boulders. These collisions generate large amounts of dust (the astreroid belt provides an example of this).
I'm not saying I necessarily belive his idea, but it's not that easy to dismiss out of hand.
Gotta love those climate models of scenarios that are impossible to compare to reality. Heck, the climate models have been SO accurate so far as far as global warming goes, why not duplicate their success with a climate model of something completely impossible to compare with reality to validate the model.
Now you are just letting a political opinion about a different matter affect your thinking.
Re:Can I be skeptical, too? (Score:1)
I agree that that isn't impossible. So if a large asteroid hits us at just the right angle and the mechanics are just right and a ring is formed which is not only optically thick but pretty dang wide, you might have something that could be visible and maybe even dim some light.
It just seems to me to be an awful lot of very improbable conditions for it to be a useful theory to explain some climate change. Essentially, the way I read it, there's some climate change they haven't been able to explain so you come up with this theory that essentially has no physical evidence. So now you are trying to explain "unexplainable" climate change with a theory that, given the odds, is highly unlikely to have even ocurred and for which there is really no evidence, let alone caused the effects on the climate they are predicting.
Me: For earth, I'm quite certain the ring would be on a smaller scale than Saturn.
You: More proof by assertion?
I will confess I can't prove how large or thick theoretical rings around the earth would be, nor can you prove that I am wrong.
However, Uranus is smaller than Saturn and all of its rings [nasa.gov] but one are listed as 0.1km thickness (the other is listed as less than 15km); compare that to a maximum thickness of 1000km for Saturn. The albedo of the rings of Uranus is also listed as 0.03, whereas the albedo of Saturn's rings goes up to 0.60.
Now that doesn't *prove* anything, but it does suggest that smaller planets have smaller rings with lower albedo.
I'm not saying I necessarily belive his idea, but it's not that easy to dismiss out of hand.
I'm not even dismissing the possibility the earth had rings. I just think it is relatively unlikely that earth had rings. And if earth had rings, it is relatively unlikely that they were large, dense, or with a high enough albedo to affect earth's climate. Given so many improbabilities I just don't acccept the theory as a reasonable explanation of "unexplained" climate change on the earth.
Me: Gotta love those climate models of scenarios that are impossible to compare to reality. Heck, the climate models have been SO accurate so far as far as global warming goes, why not duplicate their success with a climate model of something completely impossible to compare with reality to validate the model.
You: Now you are just letting a political opinion about a different matter affect your thinking.
No, my opinion of climate models is not political but scientific. I have no reason to believe climate models that actually predict LESS global warming every time they are refined. I have no reason to believe climate models that can't take 1850 climate data and, when run, produce the actual climate of the year 2000. I have no reason to believe a climate model developed by those that run their incomplete models and then turn around and suggest we make drastic changes to our economy based on the results.
As it is, climate scientists issue their doomsday reports precting all hell is going to break loose and we have to change everything now or we're in trouble--oh, and by the way, we're not 100% sure, but then the report continues on stressing the probability of the predicted effects despite the uncertainty.
As scientists making very disturbing claims of immense political and social importance, they should outright preface their predictions with "The following is based on climate models which we cannot guarantee are accurate. Improvements to this model over the last 10 years have consistently reduced the predicted impact, hence we must expect that future improvements to the model will also reduce the impact of the predictions included herein. The predictions in this report should be considered works-in-progress and only reflect one of an infinite number of possible future scenarios."
I wonder if reports had that kind of honest disclaimer whether or not politicians and the public would take them with a more appropriate level of consideration and belief. Who knows, but they probably wouldn't get any more funding.
Space Recession (Score:2)
It must have been really hard on the Saturnian tourism industry when the little blue planet up the street suddenly gets gorgeous rings for a while.
When will Slashdot Editors... um... READ SLASHDOT! (Score:1)
On tusday, Slashdot ran Earth: The Ring World [slashdot.org]
Or was that a special article that only I could see?
On the other hand, I'm really curious why Tuesday's article now has only 28 comments, while this current one, three days later, has well over a hundred. Both were in the Science section of slashdot... what am I missing?
- Peter
Re:When will Slashdot Editors... um... READ SLASHD (Score:1)
Weekend Update (Score:2, Funny)
Re:Weekend Update (Score:1)
You guessed it, Frank Stallone.
Re:Weekend Update (Score:1)
Re:Skeptical (Score:1)